Mayor Marion Barry's plan to reduce Medicaid payments for hospital clinic and emergency room visits could force some hospitals here to turn away nonemergency patients at night if implemented, hospital officials say.

Such a cut in services would affect both rich and poor alike, the officials said, and could be instituted in as many as nine of the city's 12 hospitals.

Members of the District of Columbia Hospital Association were told Friday's edition of the D.C. Register will contain official notice of the city's intention to cut the two types of Medicaid payments in half.

Federal law requires a 60-day period for comment before the changes take effect, postponing until at least the end of June of the time when the payments could be reduced.

City officials estimated the cut could generate an annual saving to the city of approximately $2.5 million a year. Hospital officials say the city may actually save closer to $4.4 million under the plan. Because the city only provides half of each Medicaid payment, while the federal government pays the rest, the actual loss to the hospitals could be as much as $9 million, the officials say.

The saving is intended to help the city close its budget gap of $175 million

In additon to reducing the Medicaid payments, the Barry administration also plans to cut other health-related programs. Under the Mayor's plan:

The $1.7 million Medical Charities program would be eliminated. That pays the medical bills for about 900 individuals or families who do not qualify for Medicaid, but are pushed below the proverty line by health care costs.

Three city clinics would be closed, which would result in a predicted saving of another $1.7 million.

The D.C. General Hospital budget will be cut by $1 million.

No new clients will be provided with homemaker services, theoretically saving the city another $1.4 million.

City officials are said to believe the hospitals will continue to see Medicaid patients, simply accepting the reduced payments for clinic and emergency room visits.

Hospital officials have stressed there is no such thing as free care. Although the care may be free, or provided at a reduced rate to the individual patient, somebody pays the bills.

Ironically, the hospitals which provide the greatest volume of service to the poor are the hospitals that will be hardest hit by the mayor's budget cuts. t

Howard University Hospital stands to lose about $3 million a year under the mayor's plan, and Children's Hospital National Medical Center, which provides about 75 percent of the pediatric hospital-based care in the District of Columbia, will lose an estimated $1.5 million.

"We would probably look to a reduction in services in some form," said Children's administrator John Mallon. "Right now we see patients in the emergency room and medical clinic 24 hours around the clock. Obviously, we don't want to cut our true emergencies, but we'd have to set up some sort of triage (priority) system, with those patients who don't need to be seen at 12 at night being told to go home and see their private doctor, or come back in the morning," said Mallon.

According to Mallon, about 70 percent of a hospital's expenses are in salaries. "The only way to reduce our expenses by $1.5 million is to reduce people," he said.

The current crisis facing health care in the District of Columbia is "a classic example of what health care providers have faced all over the country," said Steve Lipson, executive director of the District of Columbia Hospital Association," and that is the question of rationing care. The District is lucky to have escaped it for so long, New York has faced it, Philadelphia, Chicago, Detroit."